GPS Receivers

I've been using a Deluo USB GPS for a few years, it's ok but seems to come up on different ports occasionally which is a pain. Now I'm doing a permanent install I'm considering getting another GPS, so...

What are the preferred GPS receivers these days? BU-303 seems popular, Deluo now has WAAS, what should I look at for a reasonaby priced but decent unit?

Do you tend to go with serial rather than USB to make resume more reliable?

I have a Navman 100 series GPS which connects via USB. It has worked well until lately. For some reason is now takes forever to lock up, if it ever does. My cheapo handheld Garmin GPS is better in this respect!